Simple soil pH test kits are available at garden centers and through mail order. Typical ingredients to raise pH (sweeten acidic soil) would include lime and wood ashes. Typical amendments to lower (a highly alklaine soil )pH would be acidic organic materials such as pine needles or oak leaves, faster acting would be aluminum sulfate.

Keep in mind that most landscape plants will grow well in a wide range of soils so testing might not be necessary - unless you're growing plants with a definite need for acidic or alkaline soils. Examples might be blueberries which require highly acidic soils or lilacs which grow best in alkaline soils.